The present invention relates to a semiconductor device, and more particularly to a semiconductor integrated circuit device having a wiring including a wiring layer such as aluminium layer or silicon layer and a metallic film such as titanium film or platinum film deposited on the upper or bottom surface of the wiring layer.
Heretofore, in a semiconductor integrated circuit device, a metallic film of refractory metal having a high melting point is deposited on the upper surface of a wiring layer of aluminum. This film improves the corrosion resistance of the wiring layer, prevents a bulging of the wiring layer due to heat-treatment. Thus, the film prevents short-circuits between the wiring layers in multi-layered wiring. The metallic film is often deposited also on the lower surface of the wiring layer to improve the adhesion between the wiring layer and an insulating layer, therebelow. If the wiring layer includes a polycrystalline silicon, the metallic film of refractory metal is sometimes disposed on the upper surface of the wiring layer in order to reduce resistance of the wiring as a whole. Therefore, the metallic film of refractory metal is widely used in the wiring structure.
However, in this wiring structure, a contact failure problem, that is an open circuit problem, is likely to occur responsive to the flow of current at a contact portion which is used for connecting one wiring to the other wiring.